Oven for dry distillation of shales and the like



March 10, 1931. J. G. GRONDAL ET AL OVEN FOR DRY DISTILLATION OF SHALES AND THE LIKE 5 Sheets-Sheet 1 Filed March 18, 1927 March 10, 1931- J. G. GRONDAL ET AL 1,796,264

OVEN FOR DRY DISTILLATION OF SHALES AND THE LIKE Filed March 18, 1927 3 Sheets-Sheet 2 Carl L0! ns'Car/son 'W March 10, 1931. J. GRONDAL ET AL 1,795,264

OVEN FOR DRY DISTILLATION OF SHALES AND THE LIKE Filed March 18, 1927 I 3 Sheets-Sheet 3 IN VE N TORS Jo/za/z Gustaf 616mb! Cari Lor ks Car/son lm awe dftorne Patented Mar. 10, 1931 warren stars Learn 5 PATENT Jonson e'us'rar enennanann cant eannecanteen, or sroomomr, SWEDEN, AS-

srenoas re rarnnranrIEBor-aem'unclean-amen, or scrooxnoms, swnnnn,

A LIMITED GOMPANY OVER" FOR DRY DISTILLAQTION 0F SEALES AND THE LIKE x'lpplicatiea. filed Karen 18, 192?, Serial No. 178,550, and in Sweden October 7, 1926.

At the distillation of bituminous shales, brown coal and the like ovens have already been used, provided-With a grate movable through them and supporting the material, which is heated by passing a current of indifferent gases therethrongh. In such ovens, however, the shales become sticky and stop up the openings between the grate bars, thereby preventing the passage of the gases through the shales and necessitating a cleaning of the grate. Such a cleaning, however, is not possible during the process of distillation, which for that reason must be interrupted, whereby a continuous working will I be prevented.

This inconvenience may be avoided b the use of the oven forming the object 0 our invention, which oven also is provided with a movable grate, but in connection with certain means for prevention of the sticking together =of the'material viz. the stopping up of the grate.

The oven is of the tunnel type with a grate movable along the tunnel. The grate may be either straight or form an endless track, passing around on rollers or the like. Inthe oven, ventilators are arranged above the grate with the purpose of sucking away the gases formed during the distillation of the shales and forcing sa'id gases down through channels in the oven walls into the lower part of heating elements, arranged in a channel, heated by means of hot gases from one or more fire places outside the oven. I The gases passing through the heating elements hereby will become heatedto a temperature, required for the distillation of the shales, rise through the grate with" the shales and under the action of the ventilators will continue their circulation in the or en together with new-formed gases. The oven chamber above the grate as also that part of it which is situated under the heating channel, by means of vertical cross partitions is divided in compartments, communicating with one another and each passed one or more times by the circulating gases. Because these partitions do not closely fit to the grate or the heating channel. the said gases pass successively 'forward along the oven to the adjacent compartment according as new gases are formed. The steam generated at the distillation of the moist shales, ususally containmg 15 %20% water, is forced to successively pass through the grate and the shales upon same, whereby as also by the circulation of the gases the sticking together of the shalesviz. the stopping up of the grate and the decomposition of oil gases distilled off will be prevented.

Should the percentage of water of the shale be under 20%but the shales at the same time be rich in bituminous components more steam must be introduced in the oven. This can be made by cooling the escaping gases, essentially consisting ofsteam and oil gases,

. to about 100 C., whereby the greatest por-' tion of the oil will be condensed, while the water remains as steam; A greater or less part of the gases thus cooled is carried back. to the. oven, whereby a necessary addition of steam then will Be realized.

If the quantity of steam introduced in the oven becomes too small because of any negligence in the attention to the oven, and the shales consequently sticktogether on any part of the grate, the resultwill be that only such shales as stick together will be incompletely distilled, the shales on the rest of the grate being completely distilled. When the part of the grate carrying the incompletely distilled shales leaves the distillationchamher (see Figures 1-3), this part can be easily cleaned without any interruption of work. I

In the drawings, in which like parts are designated by the same reference characters,

Figure l isa longitudinal vertical section of a distilling oven according to the invention, provided with a straight track of grate formed by a number of small grates arranged one after the other and carried on rollers or wheels;

Figure 2 is a longitudinal horizontal section thereof;

Figure 3 is a transverse vertical section thereof;

Figure 4 is a longitudinal vertical section of a modification of the invention;

Figure 5 is a longitudinal horizontal section of the modification;

Figure 6 is a transverse vertical section of before and after the distillation in the intermediate compartment d'. The oven D, however, can also consist of a single, undivided channel as shown in Figs. 4, 5. e

In the constructional form illustrated in Figs. 13 the grate is formed by a number of separate, movable grates each consisting of grate bars or perforated plates A, supported by rollers or wheels 0 and surrounded by an upstanding edge B, the height of which suitably corresponds to the thickness of the layer of shades upon the grate. e are the ventilators for removal of the gases of distillation from the shales, and f the channels in the side walls of the oven, through which channels the said gases are forced to the heating elements g, arranged in the heating chan-v nels h, i. In place of two such heating channels only one a may be used as illustrated in Figs. 4, 5. 7c and 7c represent'the partition walls for the division of the oven chamber in several compartments. I

This grate is moved through the furnace in the following manner. The dampers m and m are open and by means of the device 0 the grates A, connected with oneanother, are fed to the chamber d, from which :1 corresponding number of grates is removed to, the chamber d The dampers and m now are shut, w and w opened and new charged grates are introduced in the fore chamber d, whereupon the damper a is shut. Simultaneously the grates in the chamber 03 are removed and the damper m shut, whereupon the operation now described is repeated.

It will be suitable to havethe length of the chambers 11 and d as large as possible, because m such a case it W'lll not become necessary so often to open the dampers m and a -which provide the connection with the outer air, and thus to save the heat. 7

In place-of the constructional form of the oven, now described, the modified form, illustrated in Figs. 4-8 may be used, in which the grate consists of a chain grate, formed by sets of links 2, connected by cross bolts 3 and separated from each other by interspaces of about the same width as that of the links. This endless chain grate is supported by rollers 14 andprovided with upstanding edges 11 for preventing the dragging of the shales or the like against the walls of the oven. The grate moves over two drums 4, 5, of which the first one 4,-forming the driving drum, is pro vided with shoulders or projections 6, corresponding to the openings in the chain grate and having about the same height as the links. At the rotation of the drum these projections enter the said openings and clean them during the passage of the chain grate around the drum. The other drum 5 is adjustable from the outside of the oven, so that the grate may be stretched, if required, by means of a stretching device 13. Under the driving drum 4 there is arranged a scraper 7 acting upon the chain grate by means of which the outer surface of the grate'may be cleaned.

At the end of the oven, above the grateone or suitably two feeders 8, 9 are situated, the rear one 8 of which, in the direction of movement of the grate, being destined for coarser and the fore one 9 for finer material. At the feeding of the material into the oven the finer material thus will drop upon the coarser and thereby will be prevented fromdropping down through the grate. The thickness of the two layers fed upon the grate may be regulated by adjustment of the intermediate partition wall between the funnels in vertical direction. After the distilling process the remaining goods is removed through a funnel 10, which suitably may be arranged in such a manner, that the goods resting after the distillation can be removed without thereby causing an loss of gas; The gas resulting from the distillation is removed through the outlet conduit m, after having been passed forward through the oven due to the partitions is and is not closely fitting the grate or heating channel as has been explained before,

and is then treated to remove-the valuable constituents therefrom.

The chain grate after having passed the operation, what we claim is:

1. An a paratus for the distillation of bi'- I tuminous 's'hales, brown coal and the like,-

consisting of an elongated oven, a perforated grate travelling through the oven and dividing the interior of the oven into longitudinal chambers, channels in the sidewalls of the oven connecting and connn micating with thelongitudinal chambers, thus forming a passage for the circulation of the gases of distillation, heating means in the said passage and interior of the oven into longitudinal 0 means for bringing the said gases in circulation.

2. An apparatus for the distillation of hituminous shales, brown coal and the like, consisting of an elongated oven, a grate composed of separate perforatedlbottoms travelling through the ovenand dividing the interior of same into longitudinal chambers, channels in the side walls of the oven connecting and communicating with the longitudinal chambers, thus forming a passage for the circulation of the gases of distillation, heating means in the said passage, and means for bringing the said gases in circulation. I

3. An apparatus for the distillation of hituminous shales, brown coal and the like, consisting of an elongated oven and an endless grate provided with perforations, drivin drums for moving the grate and provide with projections cooperating with the perforations and servingto clean them, longitudi-' nal chambers above and below the material supporting part of the grate, channels in the side Walls of the oven connecting and communicating with the chambers, thus forming a'passage for the circulation of the gases of distillation, heating means in the said passage, and means for bringing the said gases in circulation. v

4. 'An apparatus for the distillation of hituminous shales, brown coal and the like, consisting of an elongated oven, a perforated grate travelling through it and dividing the ambers, channels in the sidewalls of the oven connecting and communicating with the longitudinal chambers, cross partitions in the upper and lower part of the oven chambers forming compartments therein which communicate with one another, means for circulating the gases and means for heating the gases arranged in the passage for the circulation of the gases.

5. An apparatus for the distillation of hituminous' shales, brown coal and the like,'consisting of an elongated oven, a perforated grate travelling through it and dividing the interior of the oven into longitudinal chambers, channels in the side walls of the oven,

connecting and communicating with the longitudinal chambers, thus forming a passage for the circulation of the gases of distillation, a heating duct arranged in'the said passage, and transverse tubes provided in the heating duct intended to be assed by and to heat the circulating gases 0% distillation.

6. An ap aratus for the distillation of hituminous s ales, brown coal and the like, consisting of an elongated oven, a perforated for the circulation of the gases of distilla- JOHAN GUSTAF GRONDAL. CARL LORENS CARLSON.

grate travelling through it and dividing the interior oi the oven into longitudinal chamhers, channels in the side walls of the oven connecting and communicating with the longitudinal chambers, thus forming a passage 

